
import java.util.Scanner;

public class Main {
    public static String func(String scaan) {
        boolean[] booleans=new boolean[255];
        StringBuilder sb=new StringBuilder();
        int ch1;
        for (int i = 0; i < scaan.length(); i++) {
            char ch=scaan.charAt(i);
            if (booleans[ch]==false) {
                sb.append(ch);
                booleans[ch]=true;
            }
        }
        return sb.toString();
    }
        public static void main (String[]args){
            Scanner scanner = new Scanner(System.in);
            while (scanner.hasNextLine()) {
                String scan = scanner.nextLine();
                String ret=func(scan);
                System.out.println(ret);
            }
        }
    }